Adhesive composition



sepf.z8,1937. Y .,SLOMON l2,094,220

ADHES IVE COMPOS ITION Filed Nov. 18, 1935 y Ime/wit, y jwf `olfmfz Patented Sept. y 28, 1937 UNITED. STATES PATENTOFFICE f `2,094,220 l i f ADHESIVE coMPosr'rroN n v n v Ira I.' Slomon, Hollis, N; Y. K 1 ApplicationNovember 18, 19315, Serial No.750,y461

s claims. `v(ci. iaizasy `This invention relates to an `adhesive composition and method of manufacturing the same, y

and more particularly -to an improved adhesive of the type which is capable of separably unitingvarious" objects.. y

It is well'known that ordinary glues, pastes, and cementsare adapted toform an' essentiallyv permanent bond between the objects ormaterials which are united thereby. Accordingly when materials arev once joinedby the Commonly used types of adhesives, separation of the'parts is rendered difficult, and whenaccomplishedyin a1- most every instance the materials are definitely y marred in appearance as a result. v'I'hese characteristics of glue and similar cements are due to the fact that they display vagreat aflinity forall objects or materials'with which they 'come in contact ywhile wet .or moist, and quickly k'dry and create 'a strong'bond, Awhich cannot` be broken `without thev rundesirable results mentioned.

v(Dwing to these important disadvantagesy of ordinary adhesives, itis common practice to avoidr their use, whenever it is desired'to obtain a temporary or separable unionbetween objects or materials. For example, letters, papers, and correspondence are almost invariably clipped together instead of being pasted'. There are many instances, however, 'where an adhesive must be employed in spite of its usual disadvantages, because vkthere is 'no other way of causing the desired, union. i i

Accordingly a vprincipal object ofthe present l invention is to produce a new adhesive material of suilicient strength to provide a good bond between the surfaces to be united but at the same time of such a nature that the surfaces ymay be easily and quickly separated Without altering their appearance or Votherwise causing damage thereto.` 'Ihe new adhesive composition which I have discovered is not only thoroughly capable of accomplishing the above results but also possesses an unusual amount ofsubstantially permanent tackiness, so that the-adhesive maybe used continuously or repeatedly over an extended period of time without losing its adhesive properties.' In use the adhesiveis applied as a coatmg upon one surface and becomesxpermanently 'ester gum is added to a relatively large portion of .the rubber' solution. For example, a very suitable adhesive havingall of the desired properties attached thereto in the same manner as an ordinary adhesive, such as glue.'v My'adhesive differs, however, from ordinary adhesives, in that it forms a tacky layer, upon drying, and this tacky layer orfcoating is capable of 'adhesively unitingr the surface or material to which it is applied to another surface or material without creating a permanent bond, f in' other words, the

lthe surfaces tojwliich it is applied, nor will it cause shrinkage andtherefore wrinkling of such materials 4as paper.l Moreover it may be lem--` ployed to join togetherfin al11possib1e combinationsa wide variety of different materials, ,such as, paper, cardboard, glass, Wood, cork, metals,` fabrics,` cellophane, tinsel, fringe, lacquer cording and other objects rhaving a solid or semisolid surface. Y

The invention broadly relates to an adhesive composition for the purpose specified comprising a mixture, of two solutions, one of which is a solutionrof rubber 'or rubber-like material and the yother/a `solution of a lresinous material. f The bulkof the adhesive comprises a solution of rubber =while the second solution,` which is em,b ployed in relatively small quantities, comprises a. suitable solution of an ester` gumor'other similar resinous material. v n

The following is an example of a. composition which I4 have found to make avery suitableeadhesive for the purpose contemplated,` together `with the' proportions andamounts employed. 35`

.Y y solution, 1 L

Mined crepe rubber- 11b.

Naphtha 5----1 21A gals.

' j' .SoIutionZk 40 Ester gum 4 lbs. Tnlunl f 25.6 OZS. Ethyl acetate 19.2 ons; Butyl acetate. 6.4 ozs. 45

A relatively rsmall portion of the solution of may be obtained by pouring from about 5to 15 ozs. of the ester-gum solution into s ufllcient of the rubber solution to make a total yield of about one gallon (128 ozs.), and thoroughly mixing` the v:resulting product. These amounts are preferred,

as the ester gum solution, which tends to increase the tackiness of the flnal product, may produce too tacky a product, if too much is added, and if too little is employed, the advantageous characteristics of my invention may be partially sacriflced. The proportions may, however, be varied within reasonable limits, as it is sometimes desirable to diminish or increase the tacky state of the adhesive to conform with requirements under various working conditions.

It is to be understood that any other rubber material may be substituted for crepe rubber, such as, synthetic or reclaimed rubber. The rubber may also be either milled or unmilled, but better results have been obtained with milled rubber, the only advantage of unmilled rubber being its relative cheapness. The rubber may be colored or rendered white, and may have small quantities of Whiting, zinc, carbon black, or the like, added thereto for coloring and other purposes.

Naphtha is a good example of a solvent for the rubber material and may be of any'desired gravity. Any suitable solvent, however, may be employed, such as, carbon bisulphide, benzol, or carbon tetrachloride. When it is desired to render the adhesive non-inflammable, carbon tetrachloride or other solvent having lire extinguishing properties, is preferred.

The ester gum, which is obtained by reacting rosin with glycerine, is for several reasons the preferred resin for imparting to the rubber .solution the desired properties. In the first place, it is light in color, and therefore does not affect the color of the finished adhesive. Secondly, it dissolves readily in my solution, and thirdly it gives uniform results owing to its synthetic derivation. A number of other synthetic and natural gums could be substituted, but most of these are dark in color, require dewaxing, and otherwise are lacking in the advantageous characteristics of the ester gum I employ.

The toluol constitutes a solvent for .the ester gum, and can be employed in greater or less amounts according to the viscosity of final product desired. The ethyl and butyl acetates, on the other hand, act as diluents and are examples of relatively fast and slow volatiles respectively, the proportions of which may be varied to obtain a final product of varying degrees of tackiness. Equivalents of toluol lmay be added, and instead of the ethyl and butyl acetates, other esters, such as amyl acetates, secondary amyls, acetone, butone, ketones generally, alcohols, esters of the cellosolve group, otherwise known as the glycol ethers, and other solvent esters which are commonly used in the manufacture of lacquer, may be utilized. It has been found, however, that toluol is the most suitable solvent for the ester gum, and that the particular blend of ethyl and butyl acetates disclosed above is superior to other diluents, in that it produces the desired drying end point and in addition has a very satisfactory odor. By drying end point I refer to the state of tackiness of the adhesive after the adhesive has been applied and the normal evaporation of the solvents has taken place.

In preparing the composition the following procedure is preferably followed: The rubber material is placed in an iron churn and is covered with the solvent, such as naphtha, and allowed to remain therein overnight during which time it becomes thoroughly saturated. It is then agitated until a clear solution is formed. At the same time that the rubber is treated with. a Solvent, the

ester-gum is powdered and brought into solution in the toluol, and is permitted to remain thirtysix to forty-eight hours in solution. Predetermined amounts of ethyl and butyl acetates are then added, and the materials are placed in a sealed barrel and permitted to remain therein without agitation until the ester gum is thoroughly dissolved. The barrel is rolled occasionally, however, to keep any sediment from forming at the bottom. Upon obtaining these two solutions i. e. the rubber .solution and the ester gum solution, in the above manner, they are mixed, and this is preferably accomplished by pouring the ester gum solution into the rubber solution. The mixture is finally agitated so as to distribute the gum solution in the rubber solution, and the resulting material constitutes the adhesive composition which I have found to possess all of the desired characteristics.

It is preferable to add the ester gum solution to the rubber solution, because in this manner' it is possible to obtain a thorough mixture, and the amount of tack and viscosity can be controlled at all times. Moreover it has been observed that unless the mixing is accomplished in this way, the ester gum solution tends to cling to thewalls of the mixing chamberor the parts of the agitating device employed.

Some of the practical adaptations of the invention are illustrated in the accompanying drawing, of which Figure 1 represents a cotton ball to which a braidedmaterial is adhesively applied, the braided material being shown partially removed;

Figure 2 represents a metallic letter or number having a cork base, the back surface of which is adapted to receive the composition constituting the invention;

VFigure' 3 shows a similar letter or number made of cardboard;

Figure 4 shows the adhesion of tinfoil on wood, and

Figure 5 illustrates an ornamental box having an ornamental ribbon adhesively applied thereto.

In Figure 1, an ornamental tassel for curtains or the like is shown, comprising a compressed cotton ball IIJ having an exterior coating II of the special adhesive constituting the invention. The braid I2 is wrapped about ball I0 in the manner shown, and becomes adhesively united thereto upon contacting the tacky surface of the ball.

When the adhesive described herein is employed' the braid may be readily removed for cleaning or exchanged for a new braid, and in any event the braid may be reused any number oi times, as the adhesive remains intact on the surface of the cotton ball and does not stick to theA braid.

In Figure 2, I3 represents a metallic letter or the like having a cork base I4, the composite article being adapted for application to any surface, such as a door or window or'display counter. The adhesive coating I5 in this case is applied to the back surface of the cork layer I4. Thus, a letter or word may be firmly but removably fastened to any supporting surface.

Figure 3 shows a similar letter made of a cardboard layer I6, to the back of which the adhesive coating I'I is applied. In Figure 4, a laminated construction is shown comprising a layer I8 of tinfoil and a layer I9 of wood. \These layers are suitably united by my special adhesive composition, and thereby form a laminated material which is suitable for imitating metal under certain circumstances, such as, metallic configurations on windows or the like.

Figure 5 illustrates an ornamental box 20, such as is used in the confectionery trade. A ribbon Il having an ornamental bow 22 is adhesively united to box 20 bythe adhesive'material 23 of the type described herein.

`The adhesive when applied to a surface ofany material, imparts to that surface a tackiness which permits the material to be firmly yetr removably united or attached any number of times l. to a surface or any other solid or semi-solid material. In addition to this, upon separation of they two surfaces or materials, all of the adhesive material remains on the surface upon which it was originally applied and none of it is taken u up by the surface to which the coated material or surface is united. This most important attribute of the adhesive appears to be a result of the fact that it is capable of exerting a strong amnity for one material only, and, although it mayretain its adhesive properties with regard to other matev rials, it does not have any permanent union with or attraction for these materials. It should be observed, however, that when both surfaces to be united are rst treated with my adhesive, the

u resultingadhesion becomes positive, that is, the

surfaces cannot be separated without material damage. It is, therefore, essential that the adhesive be permanently applied as a coating to one` I naphthatand the ester gum solution consisting ,of substantia1ly'4 pounds of esterA gum in 25.6 ounces of toluol, 19.2 ounces yofethyl acetate, and for any material to which it isapplied, but when surface only. m It has been found that the adhesive composition constituting the invention has great affinity thisy material comes in contact with another sur face or ymaterial, the adhesive exerts no permar 35 nentfailinity for the second material, ibut creates an adhesive union between the materials whichl is `relatively strong yet the materialsmay besepa.- rated with relative ease andwithout leaving blem-y ishes or marks on the untreated material- -f ing and the like, after which the solution is per- The adhesive solution may be appliedv tothe various surfaces or materials to be treated by any f suitable method, such as dipping,'coating, spray- 1 ample, it may be applied either to the ballor the braid shown in Figure I, or to the box or the ribbon shown in Figure 5.

' It will be understood that the various applications of the invention illustrated in the drawing are merely exemplary, as many other uses and applications of the invention will become apparent to those skilled in the art. Also the amounts of the ingredients given in the example may be,

varied somewhat without detracting from the desirable attributes of the final product, although the amounts and proportions disclosed have been `found to yield an excellent adhesive for the pur,- `poses contemplated.

ture ofy a rubber solution, a solution of an ester gum, and a diluent comprising ethyl and butyl acetates.

2.- An adhesive composition comprising a mix-k -25 ture of about 113 to 123 ounces of `a rubber solution with about 5 to 15 ounces of a solution of r ester gum, the'rubber solution consisting of about 1 pound of` milled crepe rubber in 21/2 gals. of

6.4 ouncesgof'butyl acetate.` l i 3., A process for controlling the tackiness of a rubber-estergum adhesive composition compris`l ingy incorporating therein a mixture of ethyl ace- .tate and butyl acetate.

4.' A .process for controlling the tackiness `ofy a ifrubber-esteri gum adhesive composition compris- 'fing combiningf dissolved rubber with a dissolved lester vgumin the `presence of` ethyl acetate and butyl acetate y v 5. An Vadhesive composition comprising a rubbergsolution,asolution of an ester gum, and a tackiness controlling diluent consisting of ethyl l acetate andxbutyl acetate. A IRALSLOMON 

